The present invention relates to a supporting device of an optical pickup for reproducing data on an optical disk such as a compact disk (CD) and a laser disk (LD).
The pickup is supported by a tilt adjusting device for adjusting the optical axis of an optical system of the pickup to the inclination of the disk.
FIG. 7 shows a tilt adjusting device. A holder 1 of an optical pickup P is secured to a carriage 9b which is adapted to be traveled along a guide shaft 9a. An end of the guide shaft 9a is secured to a rotating shaft 9d, which is supported in a supporting device 9c, thereby supporting the guide shaft 9a in the form of a cantilever. The rotating shaft 9d is provided to be pivoted by a driving device provided in the supporting device 9c. An optical disk D is supported by a clamper 9f and rotated by a spindle motor 9e.
Inclination of the disk D is detected by a sensor (not shown). For example, when the disk D is inclined from a horizontal line D, as shown in FIG. 8, the guide shaft 9d is pivoted from a horizontal position 9a, to an inclined position 9a by the driving device in the supporting device 9c so that the optical axis O of an optical system P1 of the pickup is tilted to a perpendicular position with respect to the inclined disk D. Furthermore, the holder 1 is moved along the optical axis O so as to focus the optical system P1 as shown by dot-dash line in FIG. 8.
However, the moving distance of the holder 1 at the focusing is relatively long because the holder 1 is moved along the optical axis O only. Consequently, a driving device including a focusing coil, magnet and circuit for moving the holder becomes large in size.